皮鞋成本指的是在通货膨胀时，货币的购买力在下降，为了减少损失，人们会更倾向于持有更少的现金而将更多的钱存入银行，更多的是被迫兑换为其他国家货币。

当发生通货膨胀时，资金贬值，假设没有获得更高的资金回报的途径（没有其他渠道保值增值资金）的话，人们更倾向于把钱存入银行，以便获取利息收入来抵消通货膨胀对货币购买力的削弱。为了尽可能把钱放入银行、减少手上持有的货币，办法是每次尽量少取钱，虽然这样会增加取钱的次数，但可以使存在银行的钱尽可能的多。例：在通货膨胀时期，某人甲每月生活费1000元，相较于月初一次取1000元，甲更愿意分多次取钱，如每3天取一次，每次取100元。（这样可以赚取更多利息）。由于频繁地光顾银行，必然使鞋底磨损得较快，所以将这种成本称为鞋底成本。

“皮鞋成本”也称为“鞋底成本”，对应的英文表达为shoe leather cost。Wikipedia中给出的释义如下：

Metaphorically, shoe leather cost is the cost of time and effort (or opportunity costs of time and effort) that people expend by holding less cash in order to reduce the inflation tax that they pay on cash holdings when there is high inflation. These costs include, having to make additional trips to the bank, not being able to make change, or not being able to make unexpected purchases. The term comes from the fact that more walking is required (historically, although the rise of the Internet has reduced it) to go to the bank and get cash and spend it, thus wearing out shoes more quickly. A significant cost of reducing money holdings is the additional time and convenience that must be sacrificed to keep less money on hand than would be required if there were less or no inflation.